异常信息如下：
org.apache.zookeeper.server.admin.AdminServer$AdminServerException: Problem starting AdminServer on address 0.0.0.0, port 8080 and command URL /commands
at org.apache.zookeeper.server.admin.JettyAdminServer.start(JettyAdminServer.java:107)
at org.apache.zookeeper.server.quorum.QuorumPeer.start(QuorumPeer.java:908)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.runFromConfig(QuorumPeerMain.java:205)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:123)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.main(QuorumPeerMain.java:82)
Caused by: java.io.IOException: Failed to bind to /0.0.0.0:8080
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:346)
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:308)
at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.eclipse.jetty.server.Server.doStart(Server.java:396)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.apache.zookeeper.server.admin.JettyAdminServer.start(JettyAdminServer.java:103)
... 4 more
Caused by: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:342)
... 11 more
查看日志可以发现
启动zookeeper失败提示8080端口被占用，这是zookeeper3.5的特性
Zookeeper AdminServer，默认使用8080端口
解决方法：
修改zoo.cfg文件的配置，添加如下配置
admin.serverPort=8888
修改后再次启动zookeeper，查看启动日志，启动成功。
** adminServer的相关配置可以查看zookeeper源码了解 **
